The AN/PRC-6 circuit uses 13 vacuum tubes for the receiver and transmitter combined, all but one subminiature. The unit may be changed to a different frequency in the field by replacing the crystal and adjusting tuned circuits, using tuning indicator ID-292/PRC-6. The tuning chart inside the case is not accurate enough to properly align the unit. The AN/PRC-6 uses a 24 inch whip antenna, with a BNC connector for an external direction finding antenna. There is an optional handset H-33*/PT that can be connected to the AN/PRC-6 by a 5 foot cable. The RT-196 can be carried over the shoulder using a provided web sling.